What If Hurricane Katrina Hit New Orleans Today?

Amber Angelle | August 27, 2010 03:34am ET

Five years ago, Hurricane Katrina ravaged New Orleans with a 28-foot
(8.5 meter) storm surge and 2 feet (61 centimeters) of rainfall. The
water easily breached the city's old levee system in about 50 places and
damaged half its water pumping stations. By the time the storm had
passed, the majority of the Big Easy was submerged.

"The extent of damage was more than anyone could have imagined," said
J.W. Sneed, deputy mayor for public safety and director of the New
Orleans Office of Homeland Security & Emergency Preparedness.

Since then, government officials and scientists have sought to
transform the lessons learned from that damage into better policy. But
the city is still recovering, and much work remains to be done to reduce
its vulnerability to future Katrina-like storms.

Rebuilding natural protection

For centuries, Louisiana wetlands have acted as a natural buffer
against hurricanes by slowing down storms, reducing wave size, and
decreasing the energy of storm systems. According to scientists at the
Louisiana State University Hurricane Center, existing wetlands reduced
water speed from 7 to 3 feet per second (2 to 1 meters per second)
during Katrina.

Over the last 70 years, however, an area of wetlands the size of
Delaware has disappeared. After Katrina, the state recognized the danger
of losing more wetlands and created the Coastal Protection and
Restoration Authority. In a report last year, the agency recommended
coastal restoration measures to repair some of the damage done by
pipeline construction, poor urban planning and natural subsidence
(sinking of land).

Today, the U.S. Army Corps of Engineers is working to implement some
of these measures. They plan to divert Mississippi River freshwater,
nutrients and sediment to rebuild and sustain wetlands. The region will
benefit from these improvements, should a major hurricane strike in the future, according to the agency.

Engineering a new levee system

According to a 2006 investigation by engineers at the University of
California at Berkeley, sections of New Orleans' levee system were
incomplete and eroding when Katrina hit. The levees were almost 2 feet
(61 centimeters) below their original elevations because of subsidence
and unstable soils.

Moreover, a U.S. Army Corps of Engineers task force found that none
of the city's pump stations were working during Hurricane Katrina. The
pump stations should have drawn floodwaters from the streets into nearby
lakes once the levees were breached, but they simply weren't designed
to handle that volume of water.

So far, Corps engineers have increased levee height and replaced many
of the old levee system's concrete I-shaped walls with T- and L-shaped
walls, which consist of steel support beams that extend as far as 65
feet (19.8 meters) below sea level and will provide better support,
should the levees fill to near capacity during a future storm. Pump
stations are also being storm-proofed.

Hurricane Katrina also illustrated
to engineers that the traditional, wind speed-based Category 1-5 system
of rating hurricanes is not an accurate predictor of how a storm may
affect a city. In repairing and renovating New Orleans’ 350 miles (563
kilometers) of levees and floodwalls, the task force is using a
different type of hurricane modeling — based on storm size and intensity
— to ensure that the new system provides protection that can stand up
to 100-year storms.

When finished next year, the $14.45 billion Hurricane and Storm
Damage Risk Reduction System will give New Orleans the most advanced
defense against flooding in the city’s history.

Preventing complacency

The protection offered by coastal restoration and levee system
improvements would be undermined without effective emergency management.

"Katrina began as a hurricane but only became a disaster
because of significant, preventable planning and management failures,"
according to a 2006 paper from Victoria Transport Policy Institute in
Canada.

The city failed to use public transportation, such as buses, to
evacuate residents. Those with cars were subjected to delays of several
hours on highways without the option to refuel. Communication faltered
between city authorities, state officials, shelters and hospitals.
Following the storm, half a million residents were displaced and many
were without essential supplies.

With the passing of the 2006 Post-Katrina Emergency Management Reform
Act, Congress hoped to improve communication and reduce loss of life in
the event of another Katrina-like storm.

The act reorganized the Federal Emergency Management Agency (FEMA).
It offered grants to help cities revise evacuation plans, included
provisions for better communication with non-English speaking people and
those with disabilities and recognized the evacuation needs of people
with pets. The act also increased funding for Urban Search and Rescue
teams and requires the establishment of a family registry within six
months after a storm.

The city of New Orleans has improved resident access to evacuation
and alert information. For example, they have an e-mail and text message
system called NolaReady that 13,000 residents have signed up for.

Even the best plans will fail, however, if residents don't heed
evacuation warnings, Sneed told Life's Little Mysteries. With Hurricane
Gustav in 2008, 97 percent of residents evacuated when the mayor
declared a mandatory evacuation, but with each passing year there is the
risk that people will lose a sense of urgency regarding Katrina-like storms.

"Since there has not been another major storm since," Sneed said,
"the chance for complacency to slip back in amongst our citizens is
always a serious concern."